From 7be6463835d43a60bd5febeff2f68bf0cfb31b4d Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Sun, 15 Mar 2026 11:51:37 -0500
Subject: [PATCH] xo-interpreter2 stack: refactor: move cons() pm to object2/

---
 include/xo/procedure2/ObjectPrimitives.hpp    |  5 +++-
 src/procedure2/ObjectPrimitives.cpp           | 23 +++++++++++++++++++
 .../procedure2_register_primitives.cpp        |  1 +
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/include/xo/procedure2/ObjectPrimitives.hpp b/include/xo/procedure2/ObjectPrimitives.hpp
index 46cdf80..d02ad4a 100644
--- a/include/xo/procedure2/ObjectPrimitives.hpp
+++ b/include/xo/procedure2/ObjectPrimitives.hpp
@@ -21,9 +21,12 @@ namespace xo {
             using AAllocator = xo::mm::AAllocator;
 
         public:
-            /** create primitive for fetching nth element of a sequence **/
+            /** create primitive: fetch nth element of a sequence **/
             static DPrimitive_gco_2_gco_gco * make_nth_pm(obj<AAllocator> mm);
 
+            /** create primitive: create cons cell **/
+            static DPrimitive_gco_2_gco_gco * make_cons_pm(obj<AAllocator> mm);
+
             /** create pirmitive for creating a dictionary instance **/
             static DPrimitive_gco_0 * make_dict_make_pm(obj<AAllocator> mm);
 
diff --git a/src/procedure2/ObjectPrimitives.cpp b/src/procedure2/ObjectPrimitives.cpp
index 98206d2..1cd0086 100644
--- a/src/procedure2/ObjectPrimitives.cpp
+++ b/src/procedure2/ObjectPrimitives.cpp
@@ -6,6 +6,7 @@
 #include "ObjectPrimitives.hpp"
 #include <xo/object2/Dictionary.hpp>
 #include <xo/object2/Sequence.hpp>
+#include <xo/object2/List.hpp>
 #include <xo/object2/Integer.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/stringtable2/String.hpp>
@@ -44,6 +45,28 @@ namespace xo {
             return DPrimitive_gco_2_gco_gco::_make(mm, "nth", &xfer_nth);
         }
 
+        // ----- cons -----
+
+        obj<AGCObject>
+        xfer_cons(obj<ARuntimeContext> rcx,
+                  obj<AGCObject> car,
+                  obj<AGCObject> cdr)
+        {
+            (void)rcx;
+
+            auto cdr_list = obj<AGCObject,DList>::from(cdr);
+
+            return DList::cons(rcx.allocator(),
+                               car,
+                               cdr_list.data());
+        }
+
+        DPrimitive_gco_2_gco_gco *
+        ObjectPrimitives::make_cons_pm(obj<AAllocator> mm)
+        {
+            return DPrimitive_gco_2_gco_gco::_make(mm, "cons", &xfer_cons);
+        }
+
         // ----- dict_make -----
 
         obj<AGCObject>
diff --git a/src/procedure2/procedure2_register_primitives.cpp b/src/procedure2/procedure2_register_primitives.cpp
index f0aa6f1..c13dd4d 100644
--- a/src/procedure2/procedure2_register_primitives.cpp
+++ b/src/procedure2/procedure2_register_primitives.cpp
@@ -62,6 +62,7 @@ namespace xo {
             bool ok = true;
 
             ok = ok & install_aux(sink, ObjectPrimitives::make_nth_pm(mm), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_cons_pm(mm), flags);
             ok = ok & install_aux(sink, ObjectPrimitives::make_dict_make_pm(mm), flags);
             ok = ok & install_aux(sink, ObjectPrimitives::make_dict_upsert_pm(mm), flags);